The present invention relates to a paving block used in a public space such as a sidewalk along a general road, a park promenade and a station square, and its installation method.
For the passage of pedestrians on a pavement or in a public space, block-shaped paving materials have been laid on a bed of sand, mortar, etc. Where the conventional block-shaped paving materials, which are chamfered at the peripheral of their surfaces by about 3 to 5 mm, are laid down, a groove with a width of about 8 to 15 mm is created between neighboring paving materials. Regrettably, in the case of a vehicle equipped with relatively small-diameter wheels and possessing a poor cushioning property, such as a wheelchair and a pushchair, when the vehicle travels on this pavement, it receives unwanted shakes deriving from the grooves between the paving materials. Besides, due to a load unevenly focused on a part of the paving materials or due to subsidence beneath the paving materials, the laid paving materials become wobbly or slanted. This causes a bump or unevenness over the paving materials, which is dangerous for the traffic of pedestrians, wheelchairs, pushchairs and the like.
Besides, the block-shaped paving material usually has smooth and flat surfaces and gets slippery in a rainy or wet condition. Since such paving material is dangerous at an inclined area, another type of paving materials having an anti-slip rugged surface are additionally laid down. For this construction, two types of paving materials, i.e. smooth/flat-surface paving materials and rugged-surface paving materials, should be available at an installation site. It is not only bothering to reserve these paving materials but also troublesome to carry out the installation process.
In order to solve the above problems, the present invention intends to provide a paving block and its installation method, which gives no unwanted shakes to a vehicle such as a wheelchair and a pushchair, which creates no bump or surface unevenness, and which is easy to install.
In order to achieve the above objects, the paving block of the present invention comprises the constitutions described below.
A paving block according to claim 1 of the present invention (hereinafter as Invention 1) comprises a prism-shaped paving block base, which has a top surface entirely formed with a plurality of grooves running parallel to each other.
A paved surface laid with the paving blocks of this constitution allows passage of a vehicle with small-diameter wheels and a poor cushioning property such as a wheelchair and a pushchair, with wobbliness and shakes being alleviated at joints between the paving blocks and hardly transmitted to the vehicle.
In a preferable constitution, a groove interval between adjacent grooves is substantially equal to each other. With the blocks being laid next to each other, an interval from a joint defined between the adjacent blocks to a groove next to the joint is equal to the groove interval.
This constitution further decreases the wobbliness and shakes at the joints.
Besides, the block base may have a smooth and flat bottom surface.
This constitution provides dual use according to the conditions and enables simple installation. For example, the smooth and flat surface can be presented as the top surface. On the other hand, at an inclined, slippery and dangerous place, the grooved surface with a plurality of grooves can make the top surface.
Further preferably, each groove has a width of 3 to 10 mm, and adjacent grooves define therebetween a ridge having a width of 3 to 20 mm. The wobbliness and shakes at the joint are alleviated and hardly transmitted to a vehicle.
In the paving block according to Invention 1 constructed as above, the block base has side walls which serve as adjacent surfaces in the block base, wherein one of these side walls is formed with a rib to engage the block base with an adjacent block base, and the other side wall is formed with an engaging groove to engage with a rib of another adjacent block base.
In installing the paving blocks of this constitution, the rib of one paving block base is engaged with the engaging groove of another paving block base. Thereby, the adjacent paving blocks are integrated together with the height of the paving blocks aligned. Consequently, even when a heavy load is imposed on a single paving block, the load is dispersed over the adjacent paving blocks and less likely to cause a bump or surface unevenness due to settlement or inclination.
In a preferable constitution, each of the rib and the engaging groove has a trapezoidal cross section, and the rib is greater in width than the engaging groove. When the block bases are laid next to each other, the rib and the engaging groove which are intended to engage together establish face-to-face contact at inclined surfaces thereof.
This constitution strengthens the engagement between adjacent paving blocks and ensures distribution of a load from one paving block to adjacent paving blocks. In addition, the adjacent paving blocks are aligned in height to create a level surface, allowing vehicles to travel more quietly.
It is also desirable that, with the blocks being laid next to each other, adjacent blocks define a predetermined width of joint between side walls thereof.
At the time of installation, this constitution can provide a certain width of joint between adjacent paving blocks in a simple manner, thus facilitating the installation.
Moreover, a projection for determining the joint width can extend perpendicularly from at least one side wall formed with the rib or the engaging groove.
This constitution simplifies the formation of joints in a predetermined width.
Another projection for determining the joint width may also extend from a side wall which has neither the rib nor the engaging groove.
Owing to this constitution, any adjacent paving blocks, regardless of their orientation, can provide a certain width of joint therebetween in a simpler manner.
Moreover, in the paving block according to Invention 1, each of opposing side walls which serve as adjacent surfaces in the block base may have a recess which cooperates with an adjacent block base to define a joint portion. In this case, it is possible to provide a joint component which is engageable in the joint portion defined by each adjacent recess.
Consequently, two paving blocks can define a joint portion by facing the recesses to each other. Installation can be conducted by means of a joint component or a joint material as required.
A paving block installation method of the present invention is an installation method for laying the paving blocks of the above constitutions, and characterized in that the paving blocks are laid on a road surface by engaging the engaging groove of one block with the rib of an adjacent block in a staggered manner.
In this installation method, provided each paving block is arranged such that the grooves run diagonally with respect to a direction of foot- or vehicle-traffic, the diagonal angle is preferably from 20 to 70 degrees.
These constitutions serve to suppress bounces of wheels of a passing vehicle and thereby to cushion the shock during the groove crossing. As a result, a vehicle is not affected by shakes, etc.
As the installation methods for laying the paving blocks each formed with a recess for the joint portion, there are employed a method of laying each paving block together with the others by engaging a joint component into the joint portion, or a method of laying each paving block together with the others by filling a joint material into the joint portion. Hence, the installation mode of the paving blocks can be suitably selected.